There she paused for a while thinking… but the temptation was so great that she could not conquer it. – Bluebeard

A man locks his home and turns the valves on some gas pipes. A woman breaks an upstairs window and runs out of her house, screaming. As she crosses a bridge, she sees monsters lash out at her and street lamps come to life. As she runs into the middle of the bridge, a car hits her. The driver gets out and goes to her side, and another man arrives and tells the driver to call 911. When the driver goes to his car, the newcomer bends over and strokes her cheek, and she begs him to kiss her. The man smothers her and leaves, and the driver returns to discover that the woman is dead.

The next morning, Hank and Nick check out the crime scene and talk to the driver, Leroy Kent. Leroy explains that the man who told him to call 911 disappeared. There’s no ID on the woman, but she’s made up for bed and wearing makeup. There are long cuts on his arms but no abrasions on her feet, and they figure she lived nearby and was running away from something.

A man checks into a downtown hotel room and receives a call. He says that he’ll call when he’s done, and then removes a Grimm-killing scythe from his case, his face transforming.

At the morgue, Dr. Harper checks the dead woman and tells Nick that there are no signs of drugs and minimal alcohol usage. The coroner confirms that she was asphyxiated after the accident. Hank confirms that she’s Faith Collins and lived nearby. Her husband Roy has a record of spousal abuse, and they go to the shop where Roy works. He is apparently shocked to hear that Faith is dead and explains that he saw her the previous night when he came home. She was on the computer on a social network and hadn’t fixed supper for him, and then she walked out when they fought. Roy claims that he stayed at home waiting for her, and insists that he didn’t kill her. The officers want to take him in for a lineup, but Roy insists that he’s innocent and refuses to cooperate.

At the station, Hank and Nick report to Renard. Faith went to a bar, the Blue Moon, but left alone. Nick suggest they check her computer friends list and learn that she posted a photo of a decorative garden. They check the GPS coordinates on the phone and confirm the park was near the bridge, and a bed & breakfast, the Bramble House. They check the cab companies and then go to the house, and Nick notes a MGB roadster parked outside. The owner, Billy Capra, tells them that Faith was there. He takes a moment to thank some departing guests, and then explains that he showed Faith the room and the garden, but she didn’t leave. Nick points out that a cab dropped Faith off but didn’t pick her up, and Billy claims that he has no idea what happened to her. As they go to check the garden, Billy bumps into Hank, who appears stunned.

In the garden in the back, Billy explains that he showed Faith his rare flowers and that she sat there alone to gather her thoughts. As they walk down the path, Hank inadvertently steps on a frog. As Billy picks it up, Nick notices his face briefly change into its goat-like monstrous form. Billy explains that the toad is an endangered species and Hank apologizes, still dazed. Nick leaves Billy his card and leaves with his partner. Once they’re gone, Billy eats the dead frog.

At the station, the Grimm reaper comes in and Sg.t Wu asks what he wants. The man explains that he’s looking into the death of a friend of his, a man who was shot by one of the officers. Wu tells Renard, who tells Wu to inform the man that it’s departmental policy that they don’t give out names. The captain orders Wu to check out the man’s background.

Nick and Hank return to the station and Nick wants to run a check on Billy. As they come in, the Grimm reaper leaves, unaware of who Nick is.

That night, Nick goes to his aunt’s trailer and checks her books. He finds an entry on a goat-like creature a ziegevolk, or bluebeard, that looks like Billy’s monstrous form. The legends talk of how the ziegevolk is an oafish creature in its human form but manages to attract women. Nick goes to see Monroe, who is practicing the cello, and asks for his help. Monroe invites him in and explains that the ziegvolks are actor types who like to be in the public eye. They attract women by giving off pheromones, and if one of them touches someone, they can completely control their victim. Monroe tells Nick that ziegvolks aren’t killers and pick out the most attractive women to rut with.

The next day, Nick and Juliette go grocery shopping and talk about chemistry. They discuss each others’ first girlfriends and then head home.

At the station, Nick confirms that the cuts on Faith’s arms were caused by common window glass. Hank hasn’t found anything on Billy from before he moved to Portland, but has found a trail of missing women who all came to Portland and then disappeared. There are also groups of women who have gone missing in other cities, but many of them were found alive and pregnant by the same father. They report to Renard, and explain that the women who survived all said they were kept in isolated conditions and exposed to some kind of gas to disorient them

At the B&B, Billy takes three plates of food down to the cellar and places them in front of three cages. As he leaves, the three women reach out and take the food. Before going upstairs, Billy turns up the gas. He then goes to the garden and puts one of the toads in his pocket. Meanwhile, Hank puts a GPS tracker on Billy’s roadster. The partners watch and wait, but realize that Billy is leaving on foot. Hank goes into the house to finds a window to use to get in so they have probably cause, while Nick follows Billy down the street and sees him eat the toad.

Hank goes in via the garden and spots a broken second-floor window. Going inside via an open first-floor window, Hank looks around. Meanwhile, Nick calls Monroe and asks for his help, offering to pay him if he goes to a bar and watch Billy. Monroe agrees once he learns that Nick is paying for his drinks.

The reaper returns to his hotel room and finds Renard waiting for him. Renard tells him to kneel and the repeated reluctantly does so. The reaper wants to claim revenge on behalf of his fallen comrade, but Renard says that he denies it and then cuts off his ear with his own blade. The captain then tells the reaper to go home and stay home, and walks away.

Monroe meets Nick, who explains that he needs to watch the ziegevolk. When Nick says that he saw Billy eating a toad, Monroe explains that Billy is a rare herder. Once he collects his money from Nick, Monroe goes inside.

Hank finds a freshly-repaired window.

Monroe spots Billy hitting on a woman and moves in. Meanwhile, Hank calls to tell Nick that he’s found the broken window and says that he’s going to try and find some of Billy’s DNA so they can confirm he’s the serial abductor.

Billy chats up a woman, Lisa, while Monroe sits on her other side and listens in. When Billy touches her, Lisa falls under his control.

Hank goes downstairs and hears a woman moaning from the basement. He descends the stairs and finds the gas piping room. Hank gets a whiff of the gas and starts to waver, and then finds a bed. He starts hallucinating, collapses, and falls next to one of the cages. One of the missing women is inside.

Monroe goes back to Nick and warns that Billy is too potent for him to approach. Billy comes out and Nick ducks out of cover, thanking Monroe for his help and telling him to go home. Nick goes after Billy while Monroe goes back into the bar and approaches Lisa. She tells him to piss off and walks away with Billy’s card

Nick tries to call Hank but gets no response. He’s unaware that Hank is unconscious and one of the women is feebly reaching for his cell phone. Billy enters his home and Nick calls the police station to have them track Hank’s phone. As he waits, he sees the woman from the bar go inside.

Billy greets the woman and asks to see his garden. Nick bursts in behind them and says that he needs to talk to the woman outside. Billy tells her to go and promises that he’ll be there. Out on the porch, Nick tells her that she walked into a police investigation and tells her to leave the premises. The station calls to confirm that Hank is in the house. Nick goes back inside and discovers that Billy has slipped away. He calls Hank’s phone and hears it ring in the basement. Going downstairs, Nick finds his partner and the three captive women. Billy locks them in and turns up the gas, and then goes upstairs and starts packing. He goes outside only to find the woman waiting for him. When she discovers that Billy is leaving, she insists on coming with him.

Nick and Hank find the door and smash it down rather than risk a shot that might ignite the gas. They burst into the air conditioning room and shut down the system just in time. The next day, the police take care of the three women but find no sign of Billy. Nick and Hank check the GPS tracking signal and get a fix on Billy’s car.

Billy has taken his newest conquest to a park to get coffee. Hank approaches Billy and he runs for it, and Nick comes at him from the other side. They corner Billy, who leaps over the wall and runs into the street… and is hit by a bus. His neck is broken and they take him away to check his DNA against the women in the missing city. As the partners leave, one of the female EMTs touches Billy and falls under his spell…